Abstract

1. Aspects of female ‘offspring size vsnumber’ strategies were studied in the viviparousCommon Lizard,Lacerta viviparaJacquin, by surgical yolk extraction from ovarianfollicles and ovulated eggs in the oviduct (‘allometric engineering’).2. This method has previously been applied exclusively to oviparous lizards but hereit is applied to a viviparous taxon.3. There was a strong negative relationship between the amount of yolk removed andthe size of offspring at birth, and yolk-removed young were smaller and in poorercondition at birth than their control counterparts from within the same litters.4. In yolk-removed young physiological performance was positively correlated withbody mass.5. Maternal resource provisioning thus influences offspring physiological performance,which suggests ongoing selection on female optimization of the offspring size–numbertrade-off.